Mine



G. E. ELM.

MINE.

APPLICATION FILED ram 21. 1911.

1,430,161 Pfltentedsept- 26, 1922.

V 2 snszrs-snzn 2.

Patented Sept. 25, 1922.

UNHTEE STATES team trier.

GIOVANNI EMANUELE ELIA, OF NEW YORK, N. Y.

MINE.

Application filed February 21, 1917.

clare the following to be a full, clear, and

exact description of the invention, such as will enable others skilledin the art to which it appertains to make and use the same.

This invention relates to apparatus for destroying submarine boats andmore particularly it involves the provision of a submarine mine whichsinks when released in the sea and which is provided with automaticmeans for causing the mine to explode when it has sunk to apredetermined depth.

In order to catch and detain submarine boats, it has been common toprovide nets of considerable length which are submerged in the sea fromsuitable buoys in positions where they would be apt to be encountered byhostile submarine boats. lVhen a submarine under way engages such a net,its prow is projected between elements of the net until these parts ofthe net become wedged upon the sides of the boat and grip it so tightlythat the boat cannot release itself by backing off and frequently aneffort to detach the boat from the net results in more securelyentangling it in the net. It has been proposed to provide in conjunctionwith such nets automatic signal transmitting devices which are set inoperation when the net is drawn through the water by a submarine boat soas to transmit a signal to a receiving station indicating the presenceof the boat in the net and its approximate location. On receipt of sucha signal at the receiving station, a patrol boat would be immediatelydespatched to the locality indi cated by the signal. On its arrival atthe net, the men in charge of the patrol boat would be able to determinethe location of the boat with sufiicient accuracy, from the movement ofthe net, from the position it assumed in the water, from the positionsassumed by buoys connected with the net and in other ways, except thatthey might not be able to determine the depth to which the boat wassubmerged.

The present invention involves the provision of a mine which could beused by the man in the patrol boat to destroy the submarine boat socaught in the net. The mine is of such a weight that when released inthe Serial No. 149,978.

water it sinks and it is provided with means for exploding it which areoperated automatically when the mine has sunk to a predetermined depth.Such a mine would be released from the patrol boat, would sink to thedepth for which it had been set, and would then explode. The men in thepatrol boat would be able to determine whether or not the explosion ofthe mine had caused the destruction of the submarine boat for if ithadbeen successful, great bubbles of air .would rise to the surface andalso. oil

would appear upon the surface of the water..

If there were no such indication of success in the destruction of thesubmarine boat, a similar mine would be set for explosion at a differentdepth and would be similarly released. This procedure would be continueduntil it was apparent that the successful destruction of the submarineboat had been accomplished.

There are a number of diiferent constructions which may be employed foreffecting the automatic explosion of the mine whe it has reached thedesired depth. That which I prefer to employ is a firing mechanism whichis caused to be operated by devices whose movement is effected by thesinking of the mine through a flexible connection from the mine to abuoy floating on the surface of the water. Such a flexible connectionmay be wound a predetermined number of times around a reel or sheave inthe mine casing and attached at one end to the sheave, its other endbeing secured to the buoy. When the minesinks in the water, thisflexible connection causes the sheave to rotate and after apredetermined amount of rotational movement, the sheave may be caused tooperate or to release the automatic firing mechanism. It will beunderstod, however, that the invention is not limited to this sperificform of automatic firing mechansm excep to those claims wherein thisconstruction is specifically set forth. In its broader aspects, theinvention involves the provision of a mine having automatically operatedfiring mechanism therein which is actuated to cause the explosion of themine when the latter has sunk to a predetermined depth, irrespective ofthe specific form of the mechanism employed for this purpose.

The embodiment of the invention which is at present prefer ed isillustrated in the accompanying drawings, wherein Fig. 1 is adiagrammatic view showinga submarine boat caught in a net and a. depthmine sinking in the water adjacent to the boat from a buoy floating onthe surface of the water.

Fig. 2 is a central section of the mine and Fig. 3 is a sectionalelevation corresponding to Fig. 2 and showing a different position byweights 7 secured to its lower edge.

.The mine is shown at 8. It is of such weight with relation to itsdisplacement thatit sinks when released. A flexible cable 9 extends fromthe mine to a buoy 10 and tively to the axis of the tube.

this cable is unwound from a reel in the casing of the mine as the minesinks. The automatic firing mechanism in the mine-is actuated after thereel has been unwound by the sinking of the mine to a predeterminedextent. j

The construction of the mine itself is illustrated in Figs. 2 and 3. Itconsists of a cylindrical casing 11,'and the major portion of the spacewithin this casing is filled with the explosive 12. At the center of thecasing is a tube 13 having a support 14.

.therein fora primer 15. Above the primer is a, cylindrical weight 16carrying a ham mer 17 in' such. a position that when the weight; 16 isreleased and descends, the hammer'l'i' strikes the primer 15 and thusexplodes the mine. Above the weight 16 is a threaded shaft 18 whose endenters an opening provided therefor in the upper faceof the weight 16.The lower end of the shaft 18 is detachably connected to the weight16 bymeans of two or more pieces 19 located in radial openings in the weight16. The inner ends of these pieces19 are bevelled off as shown in Figs.2 and 3 and these bevelled inner ends are adapted to enter acircumferential groove in the lower end of the shaft. Near its upper endthe tubular member 13 is enlarged in cross-section and thetwo portionsof the tube of different diameters are connected by a portion 20 whoseinner surface is inclined rela- T'he outer ends of the pieces 19 arebevelled like their inner ends and are adapted to coact with the.inclined surface of the portion 20 of the tube; The upper end of thecasing 11 .is closed bv a wall 21 and between this wall and the top ofthe weight 16 is a spring 22 coiled about the shaft 18.

' A cap 23 is secured to the top of the casing 11 and is provided with ahorizontal wall 24. In the space between the walls 24 and 21 is a reel25. This reel is provided with a central threaded opening which receivesthe threaded shaft 18 and the upper end of the shaft projects through anopening the wall 24. The cap 23 is also provided with two or more radialinclined arms 26, one of which is hollow so as to providea passage forthe flexible cable 9. This cable passes through the passage in the arm26 and is wound around the reel 25, its end being secured to the reel.desired, the reel may be provided with ball bearings, as is indicated inFig. 2.

Means are preferably provided for guarding against rotational movementof the shaft 18 when the reel 25 is rotated. This may consist of aprojection entering an axial groove in the threaded shaft 18 andprovision may be made for withdrawing this projection to permitofturning shaft 18 manually independent of reel 25 for adjusting the depthat which the mine will be exploded. In the drawings, the axial groove inthe shaft 18 is indicatedat 27 and a projection is'shown at 28 mountedupon the wall 2 1 and entering the groove 27. This projection 28 ispivoted so that it may be turned by a handle 29 to a position in whichits end is withdrawn from the groove 27. Also, the upper end of theshaft 18 is squared so that a wrench may be applied thereto for turningit and the wall 2 1 is provided with an opening so that rotation of reel25 may be prevented while turning the shaft 18 manually.

Fig. 2 shows the parts of the mine in the posit-ions which they wouldoccupy when the mine is released on the surface of the water. By reasonof its weight relative to its displacement, the mine sinks but as theupper end of the cable 9 is secured to a buoy 10 of adequate size, thecable 9 is drawn out through the passage in the arm 26 and causesrotation of the reel 25. Turning movement of the shaft 18 with reel 25.is prevented by the projection 28 entering the axial groove 27 in theshaft 18. Theturning of reel 25 as the mine sinks, therefore causesupward movement of the shaft 18 and the latter carries with it theweight 16 compressing the spring 22. lVhen the weight 16 has been raisedby the turning movement of reel 25 so far that the pieces 19 comeopposite the inclined surface 20, the pieces 19 are movedoutwardly by.the inclined surfaces upon the inner ends of the pieces 19 and thesurfaces at the lower end of shaft 18 with which they coact. Until theweight 16 has been raised to this extent, outward movement of the pieces.19 is prevented as their outer ends abut against the wall of theportion of tube 13 which is of the smaller diameter. The outwardmovement of the pieces 19 after the weight has been raised releases thedetachable connection between the shaft 18 and the weight 16 and whenthe downwardly, the pieces 19 being moved inward slightly by theengagement of their inclined outer ends with the inclined wall 20.,VVhen this occurs, the weight 16 is moved downwardly with great forceby gravity and by the spring 22 and the hammer 17 engages the primer 15,thereby exploding the mine. Fig. 3 shows the positions of the parts whenthe weight has been raised far enough to permit the outward movement ofthe pieces 19 and just before the weight is released.

The mounting of the projection 28 so that it may be withdrawn fromcoaction with the axial groove 27 in the shaft 18, permits of adjustingthe mine for explosion at any de sired depth. To effect such adjustment,the projection 28 is withdrawn from groove 27 by depressing the handle29 on the projection. Then rotation of the reel 25 is prevented byreaching through the opening 30 in the wall 24: or by passing a shortdetent through the opening 30 and into one of a plurality of openingsprovided therefor in the flange of the reel. A wrench is then applied tothe upper squared end of shaft 18 so as to turn the shaft relatively tothe reel. The pitch of the coacting threads on the shaft and reel may besuch that each rotation of the shaft or each quarter rotation of theshaft relativelyto the reel will change the depth at which the mine isexploded a given amount, as for instance, one foot. To facilitateobtaining the desired adjustment, the upper end of the shaft 18 may havea suitable scale marked thereon as is indicated at 31, in Figs. 2 and 3.

Another way by which an adjustment can be effected to cause explosion ofthe mine at the desired depth is by adding to the length of the cable 9in such a way that the reel 25 will not be actuated while the mine issinking in the water the distance necessary to take up this added lengthof cable. For instance, a patrol boat might carry an adequate supply ofthese depth mines all set for antomatic firing at a depth of thirtyfeet. If it were found that firing at a greater depth was necessary byreason of the failure of the explosion of a mine at a depth of thirtyfeet to accomplish the desired result, another mine, similarly adjusted,would be prepared for launching by inserting a length of cable, say tenfeet of cable, between the upper end of the cable 9 and the buoy 10.

, The mine and buoy would then be launched and while the mine wassinking ten feet, the reel 25 would not be rotated to cause verticalmovement of the shaft 18. After the mine had descended ten feet, furtherdescent would cause rotation of the reel in the manner heretoforedescribed and the mine would be exploded at a depth of forty feet.

It will be appreciated that a depth mine of the character abovedescribed may be launched from an aeroplane as well as from a boatadapted to travel on the surface of the sea. The mine and its buoy maybe dropped from an aeroplane into the sea, whereupon the mine would sinkin the water while the buoy remains afloat, thus causing actuation ofthe automatic. mechanism for firing the mine.

Submarine boats are sometimes attacked while resting upon the bottom ofthe sea. If a depth mine of the type above described were launched in anattack against a submarine resting on the bottom and the mine came incontact with the bottom before its firing mechanism was automaticallyactuated, the fact that the mine had not exploded would be known to theoperators in the attacking boat on the surface from the v absence of anybubble of gas rising to the surface, such as would follow the explosionof the mine under water. By simple tests, it could be determined whetheror not the mine was resting on bottom. and if this were found to be thefact, it would only be nec essary for the operators in the patrol boatto pick up the buoy and pull in on the cable 9. This would causeactuation of the mechanism in the mine just as would occur as a resultof sinking of the mine to a greater depth and the mine would be explodedwhile on the bottom at a depth somewhat less than that for which itsautomatic firing mechanism had been set. In this connection it may bepointed out that when a mine of the type referred to. is exploded in thewater at a substantial depth, as for instance, a. depth of 100 feet, itsexplosion would involve no danger to the persons in a boat upon thesurface of the sea directly over the mine.

When attacking a submarine boat with a depth mine of the type referredto, it sometimes occurs that as the mine sinks through the water itstrikes the submarine boat and is supported thereby. This might resultin failure of the mine to explode. With the construction of mine hereindescribed the operators of the patrol boat, on noting that the mine hadnot exploded, could return to the buoy and take it in tow, therebydrawing the cable 9 out from the casing of the mine. This would resultin auto matic firing of the mine although it had not sunk to the depthfor which it had been set. This construction of mine there forepossesses this advantage over a construction in which the automaticfiring of the mine is accomplished by hydrostatic means responsive todifferences in the pressure of the water at difierent depths.

In the foregoing I have illustrated and described the construction andoperation of the embodiment of my invention which at present seems bestadapted for the attainment of the ends in view. This construction,however, may be changed in many rev invention is in no way limited withrespect to the manner in which the mine embodying the invention is usedor the particular purposes sought to be accomplished thereby. I havedescribed the use of mines embodying the invention in destroyingsubmarine boats which have been caught in submerged nets and while suchmines are of special utility for that purpose, they are also adapted forvarious other uses.

I claim:

1. The combination of a mine which sinks when released in the water, abuoy, a flexible connection from the buoy to the mine, a reel in themine with which the flexible connection cooperates, a threaded memberwhich is moved axially by the rotation of the reel, and means forexploding the mine operated automatically in response to the axialmovement of said member; substantially as described.

2, The combination of a mine which sinks when released in the water, abuoy, a flexi- 'bleconnection from the buoy to the mine,

a reel in the mine with which the flexible connection cooperates, athreaded member which is moved axially by the rotation of the reel, afiring mechanism for the mine controlled by the axial movement of thethreaded member, and means for adjusting the threaded member and thereel relatively to establish any one of a plurality of relations betweenthem so as to regulate the depth at which the mine will be exploded;substantially as described. 7

3. A mine having a reel, a threaded shaft coacting with a threadedopening in the reel, a firing member detachably connectedto the shaft, aprimer for the mine with which the member cooperates, and means operatedby a predetermined amount of. axial movement of the shaft for operatingthe detachable connection between the shaft and the firing member so asto release the firing member and permit the same to operate;substantially as described.

In testimony whereof I afiix my signature.

GIOVANNI EMANUELE 'ELIA.

